There are many versions of Windows that can be downloaded and used on the PC. Who wants to use two different versions of Windows on the computer can install the second one in dual boot or, much more easily, install it as a secondary operating system, leaving the system in use intact. If you wanted to create a dual boot of Windows 7 with Windows 10 or vice versa, without actually installing the other version of Windows in a separate partition of the disk, you can install Windows 10 or Windows 7 on a virtual hard disk (VHD) . The procedure of creating a virtual disk and installing Windows 10 is very simple and fast, without any risk of side effects.
A virtual hard disk is seen by Windows as a simple file which however contains a real operating environment inside. It is a separate area from everything else so any changes made within the VHD have no effect on the rest of the computer.
READ ALSO: Create the VHD file of the Windows PC (to be used as a virtual machine)
1) First of all, download Windows 10 (or download Windows 7) and create an ISO file to copy to DVD or USB stick.
2) Connect the bootable USB drive to the computer or insert the DVD in the player and reboot the system and setting the bios to start from USB or CD according to the chosen mode.
3) Restarting the PC, within a minute or two you will see the first screen of the Windows 10 installation wizard.
Without making any choice, instead of clicking Next, press the Shift + F10 key combination on the keyboard and see a DOS command prompt appear. From the prompt, you need to create the virtual disk by running the following commands (pressing enter after each of them).
- Diskpart
- List disk
- Select disk 0 (here you have to select the disk where the normal Windows installation is located, then the main hard disk)
- List vol
- Create vdisk file = "E: \ win10.vhd" maximum = 30000 and type = expandable (In this line, replace the letter E with the letter of the hard disk where you want to save the new installation; 30000 MB is the recommended size 30 GB for Windows 10.)
- Select vdisk file = E: \ win10.vhd
- Attach vdisk
- Exit
4) Exit from the command prompt and, returning to the installation screen, select the language and all the rest, press Next and install Windows 8 following the guided procedure. After accepting the license agreement, select the " Custom: Install Windows Only ".
5) In the next screen, select the newly created VHD virtual hard disk. If an error appears that says something like: " Windows cannot be installed on this disk ", you can ignore it and go ahead.
In the end, when you restart your PC, you will be asked to choose which operating system to start with, whether Windows 7 or Windows 10.
In case you want to eliminate the VHD, remember to fix the bootloader by restoring that of Windows 7 keeping in mind what is written in the guide on how to install two operating systems on a PC and choose how to start the computer.
However, I must warn you that this installation method is not optimal for Windows performance which may be slower and somewhat limited.
However, you can do all the tests you want, without fear of doing damage and with the possibility of opening the VHD even from a virtualization program.
